Posted
by
samzenpus
on Sunday April 01, 2012 @02:00PM
from the where-are-we? dept.

Jimme Blue writes "The use of pulsars as a GPS analogue holds the promise of fixing a spacecraft's location to within 5 km, anywhere in the galaxy. While not ready for immediate use, it may be ready for use within the Solar System in the next 10-15 years. From the article: '"The principle is so simple that it will definitely have applications," said Prof Werner Becker from the Max-Planck Institute for Extraterrestrial Physics in Garching.
"These pulsars are everywhere in the Universe and their flashing is so predictable that it makes such an approach really straightforward," he told BBC News.'"

Within the solar system, visibility to a known set of pulsars shouldn't be an issue, but as you venture outside the solar system, which pulsars are visible may begin to change as pulsars don't emit in all directions. In practice, most pulsars in a given galaxy probably rotate/emit more or less in the galactic plane, so, even within a galaxy, it's probably a good reference. But that's definitely a risky method if you start moving out of the galactic plane.

As the spaceship moves some pulsars will drop out of visibility and others will become visible - so the spacecraft can lock on to the new ones, using the old ones to calibrate them. That would work unless we develop some kind of 'jump' technology where we appear at great distance from our last position and have no pulsars in common between the two places, but that would be an interesting problem to have.

I think its awesome that while we had to build a GPS constellation for earth, the Universe has naturally provided a system usable for precision guidance for interstellar travel. Science is fucking awesome.